Re: ESR to the can?

Yeah, I checked with a 10 ohm resistor and my blue ESR shows agreement with my DMM.

I am going to have to settle on what I am seeing as a VERY low/open ESR reading. So low that it is a fault. Along with this I am also seeing the cap is shorted to the can, AC short and not DC. It is a faulty capacitor.

A note to everyone , I will continue to measure ESR to the can. I checked the capacitance of the short to the can and it is 3uF, bad design or whatever, it should not be there. Other caps I also checked to the can were faulty too. I...

Re: ESR to the can?

Sam Young series NXC ESR max 36m ohm/20C @ 100Hz, from the samyoung datasheet that is dated 10/04/07.

So, .036 max versus a reading of .00 or .01, could have been my leads not fully zeroed. These are the brown colored capacitors you typically would see in an older samsung LCD monitor.

I see nothing about reading terminals to the can. To me it looks like there would be one or two capacitors in series or parallel with the actual capacitor. Positive to the can negative to the can and the actual capacitor. Am I just looking at this wrong...

Re: ESR to the can?

So does the ac leakage to the can indicate a bad cap or is it bad design? I checked several others and some gave reading where other did not. I am trying to determine if I should always test to the can or not and I haven't seen anything mentioned anywhere about testing to the can.

I didn't do the math yet but I think that zero ESR reading is telling me that cap is bad even if it reads near right on a capacitance meter. Also about the zero reading, that changes to about .01 depending on , I think, the temp of the cap and that is only warming it...

Years ago I used to use the can of an electrolytic as a ground point when measuring voltages, it was easy to get at from the top of the board.

I have a couple of crashed Samsung 943BX (2006-8) monitors and went at them with my blue ESR meter. Right off I find two Sam Young caps, 820@25v in parallel so I tested on-board and I get zero for ESR, no bulging and the bung is inplace and it is not bulging.. I unsolder them and I get zero ESR but their capacitance is in the ballpark, I think it was 860 uF. So, I take an ESR reading from positive to the can and I get 24 ohms! Wha? I have...

Re: New Members - please post your introductions here

New member here. I have been into electronics since age 11, some time ago now.
Computers, started with a Coco and still have my original 8088.

My first screw driver was a butter knife, graduated to a pair of old needle nose pliers with cutters, AKA finger pinchers , wow! So long and so many tools ago.

I work on anything that gets in my way.

There you have it in a very small nutshell.


Thor